WannaCry
& ATMs:
Ransomeware has
created havoc in the market .Every news channel, news paper almost everyone
spoke about it. But worst part of it was, most of the information received
through TV channels, print media were misleading . In fact it was added
to panic, as if nothing like this existed before in the cyber security
world.
WannaCry (ransomeware)
exploited one of the available vulnerability in the Windows OS i.e., through
SMB (port 445 and 139). Let me don`t get into its technical details and
confuse further like others. In fact what made me to write this blog is, hardly
any news paper or news channels, gave information to user which can help to
stay them protected from wannaCry or similar attacks to common people. Moreover
what surprised me is, when I heard that even some of ATMs were shutdown because
of this worm. It was an utter shock to me. Lets understand how this
wannaCry works in simplest possible manner.
SMB protocol is used
to share the files over network which runs on port 443 and 139 and in Windows
this is default service, hence these ports are always open. So, for LAN users
this is open gate always (with some user level authentication as security
measure) and wannaCry penetrates through this door in your PC (!@#$#@#$#@
with some known vulnerability in handshake ) .
Let me equate with the real time example for non-techies:
In your house you have
multiple rooms, and you need to communicate across rooms frequently hence you
have kept the door open all the time within rooms, since you consider this as
internal matter within your house, you find its okay to keep these doors open
connecting to each room. But what happens if some outsider gains access
to your home somehow (pretending something), he will be still able to use this
open door to do anything.
Here wannaCry is
an outsider, opened doors are same as port 443 and 139, and your home is same
as the internal network or LAN and each rooms within home are like Laptops and
PCs.
What can be the lay man solution to
this, about someone who is making use of this open door facility within a house
upon someone somehow entering in the house?
1. Try prohibit this
person entering in house (which is difficult, as you can be just careful but
can’t be annoying to every guest by suspecting them).
2. Put a lock on these doors till this
guy is caught.
Similarly users can do following to stay protected.
1. Apply a firewall
rule in PC to block these ports till you upgrade with security patch or apply
the same in immediate router. , this same as putting lock on doors till
thief is caught.
2. Install Linux OS,
access windows File system through it (If you want to continue using internet
and still stay unaffected confidently) in that case you can confidently ignore
this ransomeware.
Opting Linux is like there is FREE option to move into your home in high
security zone anyway where possibility of such event is very very rare. As
Linux has default infra structure to prohibit, monitor or repair such things etc.
etc..
And above remedies are
ordinary, and even a fresh security engineer knows about it.
Let me come to ATMs now.
1. Most of ATMs which
are deployed are white labelled licenses ( which means these are general
products and can be labelled anything like SBI, HDFC etc.. ) it means
underlying software is same in every ATM. Hence it mean problem in one ATM
machine, then it exists in every other ATM machines.
2. This is Bizarre now,
most of ATM runs Windows OS with no security patch updates, which makes it more
unsecure than our Home PC, and on the other hand we have Linux Operating
System.
a. Which
is open Source (Free License).
b. More stable,
robust and secure.
Hence
choosing/demanding Linux OS based ATM is matter of basic understanding and low
cost too.
Its known fact that
most of us, generally don’t consider cyber security at priority while choosing software
(as we think we need security only for commercial transactions, lol), that’s
the reason our evaluation criteria doesn’t involve most important aspects
besides Functionality, while choosing a software product for our business. Hence
besides functionality following considerations are important.
1. Security
2. Robustness
3. Scalability
4. Performance.
5. Extendibility.
As every Software
company can provide given functionality someway, it’s important also to
consider above aspects at the same time.
What we learn from
this episode? (While choosing software for your business):
1. Choose Linux
based server side technologies (which makes it more secure, robust and less cost)
and also legally safe and lowers the cost.
2. Try to
consider closed system if possible. Which is not exposed to wider
audience unnecessarily?
3. Ask Questions about
network protocols used, and see if those protocols have history or have
possibility of threats, and see if alternate is possible for your application.
4. Find out how robust,
scalable and performance oriented designed software system is!!!
Why it’s important to
consider above points?
1.
Either way your data is important to you. It might be of any
type, You definitely don’t want any ransomware to encrypt and ask ransom money
to decrypt the same.
2. Threat
is not only ransomeware this is a very small example of number of
threats/attacks or worms exists. It just doesn’t makes sense to ignore it.
So don’t take a chance.
Finally Security consideration is necessary if you don’t; worms
like ramsomeware will force you to do that….